• Sunit Patil

Title: Mapping moduli spaces across geometric transitions and new N=1 dualities

Abstract: In this talk, I will present evidence for new dualities between 4-dimensional Calabi-Yau compactifications of the heterotic string, where the base manifolds are linked by a conifold transition. Similar 4D effective field theory (EFT) dualities are extensively studied in Type II theories, but remain poorly understood in the heterotic context. Past observations have shown that compactifications connected in this way yield 4D EFTs with identical massless spectra, a phenomenon previously studied via relabeling in the (0,2) Gauged Linear Sigma Model (GLSM), known as (0,2) target space duality. Building on a recent geometric proposal detailing how 5-branes and gauge bundles traverse a conifold transition, I will show how we construct an explicit moduli map between the field spaces of the two compactifications. This provides much stronger evidence for the duality than just spectra counting. Utilizing this map, I will demonstrate that 147,440 independent superpotential Yukawa couplings agree perfectly across the duality as holomorphic functions of the moduli. Ultimately, I will establish that this N=1 duality, connected by a geometric transition, is significantly broader in scope than the (0,2) GLSM target space duality.

• Björn Hassfeld

Title: F-Theory uplifts at large h_{1,1}
Abstract:  We present a systematic way to construct d-dimensional Calabi-Yau orientifolds and their uplifts to elliptically fibered Calabi-Yau d+1-folds, suitable for F-Theory compactifications, as subvarieties of toric varieties. We identify models in which the mirror d+1 fold can be understood in a combinatorical way making these models especially suitable for understanding the seven-brane superpotential.